Metering devices are needed, in particular, for adhesives, cyanoacrylates, instant adhesives or anaerobic adhesives and sealants. These are sold in bottle-shaped containers, wherein only minimal quantities of all these adhesives and sealants are dispensed in a metered fashion and the containers, namely plastic bottles, accordingly are relatively small. The container needs to be slightly squeezed in order to dispense the corresponding substance from a nozzle in a metered fashion. Particularly adhesives and sealants are frequently semiliquid or have a low viscosity and therefore do not flow out of the container themselves. However, certain adhesives also need to be stored in such a way that practically no oxygen admission can occur. Consequently, the plastic bottles need to be made of HDPE (High Density Polyethylene) and this material needs to have a corresponding hardness. However, this complicates the metering by exerting pressure upon the container.
It would be particularly desirable to use relatively long, pin-shaped bottles, but the smaller the diameter of the container, the more difficult its deformation for realizing the metering such that this situation represents an absolute dilemma. In addition, the container needs to be provided with a metering device in order to even allow a sensible metered dispensing of the adhesive.
U.S. Pat. No. 4,771,769 already discloses a metering device, in which a relatively small bottle can be inserted into a device that features a body, in which bottle is situated, wherein this body features a pressure lever that is coupled to the wall and presses on the edge of the bottle bottom. This solution practically is only suitable for soft containers because plastic bottles of a hard plastic, particularly a HDPE, practically cannot be deformed in the region of the particularly large wall thickness at the transition from the bottom to the container wall. In order to position the bottle in the metering device, it is furthermore necessary to unscrew the cap, to insert the open container into the device and to subsequently reattach the cap so as to fix the bottle in the device. This procedure would be completely unsuitable for a cyanoacrylate adhesive and an accidental spill could lead to substantial damages.
A much more cost-efficient variation is disclosed in WO-2004/013009-A. This publication discloses a simple and inexpensive metering device that makes it possible to dispense a liquid drop by drop. Although this document describes a number of exemplary embodiments, only one embodiment is relevant in this context, wherein this embodiment proposes a loop-shaped plastic loop that is aligned parallel to the longitudinal bottle axis and encompasses the container neck. The loop is separated in the bottom region of the bottle and adjoins the bottom of the bottle at this location, wherein the loop subsequently extends upward to the bottle neck while adjoining the container wall, over the bottle while lying on the container shoulder and then downward on the diametrically opposite bottle wall region in the form of a certain moulded bend. The bend in the region of the bottle shoulder lies on the container wall and a lever downwardly extends from the shoulder to the bottom in an angled fashion in order to once again join the loop extending underneath the bottle bottom after being bent one more time. Such a device also has the disadvantage that the pressure is excerpted exactly at the location, at which the bottle has a particularly high rigidity, namely in the region of the shoulder. Furthermore, this device is only suitable for occasional use and the device essentially needs to be detached from the bottle in order to store the container.
A metering device according to the preamble of Claim 1 is also known from U.S. Pat. No. 4,773,898. This publication pertains to a veterinary device that serves for administering medications to animals. In this case, a lever is coupled to a ring that is attached to the bottle by means of a hinge, wherein said lever has a curvature that is directed toward the bottle and serves for exerting pressure.